BAGHDAD (AP) — A terrifying wave of bombs tore through mostly Shiite neighborhoods of Baghdad on Thursday, killing at least 69 people and evoking fears that Iraq could dissolve into a new round of sectarian violence now that American troops have left.

The attacks appeared to be a well-coordinated assault by Sunni militants linked to al-Qaida and targeted markets, grocery stores, cafes and government buildings in a dozen neighborhoods. They coincided with a government crisis that has already strained ties between the two sects to the breaking point.

For many Iraqis, this could be the beginning of a nightmare scenario: The fragile alliance in the governing coalition is collapsing, large-scale violence bearing the hallmarks of al-Qaida insurgents has returned and Shiite Prime Minister Nouri al-Maliki may be moving to grab the already limited power of the minority Sunnis.

“The conditions that perpetuate civil wars are making a hasty comeback,” said Ramzy Mardini, an analyst at the Institute for the Study of War in Washington.

The bombings may be linked more to the withdrawal of the last U.S. troops Sunday than the political crisis, but all together the developments raise the specter of a return to the Shiite-Sunni sectarian bloodshed that pushed Iraq to the brink of civil war in 2006 and 2007.

Al-Maliki is engaged in a showdown with the top Sunni political leader in the country. His government has issued an arrest warrant for Sunni Vice President Tariq al-Hashemi for what al-Hashemi says are trumped-up charges that he ran hit squads against government officials.

That has thrown Iraq’s political community into a crisis, with Sunnis suspicious that al-Maliki is making a power grab in the wake of the American military departure.

Thrown into this already heated mixture was some of the worst violence Iraq has seen this year.

At least 16 blasts went off across Baghdad, killing 69 people and wounding nearly 200 more. Most exploded in the morning but at least two struck Thursday evening.

The deadliest attack was in the Karrada neighborhood, where a suicide bomber driving an explosives-laden vehicle blew himself up outside a government office. Two police officers at the scene said the bomber was driving an ambulance and told guards that he needed to get to a nearby hospital. After the guards let him through, he drove to the building and blew himself up, the officers said.

“I was sleeping in my bed when the explosion happened,” said 12-year-old Hussain Abbas, standing in his pajamas. “I jumped from my bed and rushed to my mom’s lap. I told her I did not want to go to school today. I’m terrified.”

In Washington, the White House condemned the bombings and said attempts to derail progress in Iraq will fail. Press secretary Jay Carney said the attacks serve no agenda “other than murder and hatred.”

Vice President Joe Biden, President Barack Obama’s point man on Iraq, called President Jalal Talabani to discuss the situation. It was Biden’s second round of phone calls to Iraqi officials this week.

Gen. Ray Odierno, the U.S. Army chief of staff, also visited Baghdad Thursday in what was described as a trip arranged before the political crisis erupted.

It was exactly this type of violence in the early days after the U.S.-led invasion that eventually spiraled into a near-civil war. Sunni militants such as al-Qaida saw Iraq as their battleground against first the U.S. and then Shiites, whom they do not consider as true Muslims.

Shiite militias, fired up by years of anger over repression under Saddam Hussein’s Sunni-dominated regime, then fought back in what eventually became a tit-for-tat battle fought mainly across Baghdad. A bombing against a Shiite neighborhood would be answered by residents of a Sunni neighborhood being dragged out and shot.

That’s the type of reaction that analysts say al-Qaida is trying to spark with violence such as Thursday’s blasts. There was no immediate claim of responsibility, but the bombings bore all the hallmarks of al-Qaida’s Sunni insurgents: a mix of sticky bombs, a suicide bomber, roadside blasts and car bombs.

Al-Qaida in Iraq is severely debilitated from its strength in the early years of the war, but still has the capability to launch coordinated and deadly assaults from time to time. U.S. military officials worried about a resurgence of al-Qaida after their departure.

If Sunnis feel invested in the political process and see that they have a future within it, analysts say it’s unlikely that al-Qaida and its ilk could gain much traction within the wider Sunni community, especially after the bloodbath that Iraqis have already endured and are not eager to repeat.

Many Sunnis fear the arrest warrant against al-Hashemi is part of a wider campaign to go after Sunni political figures and shore up Shiite control across the country.

In this already tense atmosphere, Hadi Jalo, a Baghdad-based political analyst, said Thursday’s violence will likely elicit an even stronger crackdown by al-Maliki as opposed to a conciliatory move.

“What is clear now is that the situation is deteriorating,” he said. “I think al-Maliki, who has the absolute power now ... will strike back, and he will escalate his crackdown against his political rivals. The situation now will continue to fuel the sectarian tensions.”

Coordinated campaigns such as this generally take weeks to plan, and could have been timed to coincide with the end of the American military presence in Iraq, possibly to undercut U.S. claims that they are leaving behind a stable and safe Iraq.

Iraqis have mixed feelings toward the departure of the American military that invaded nearly nine years ago. Their gratitude for the ouster of Saddam is coupled with anger at the violence that eventually overcame the country.

Now, especially after Thursday’s explosions, they wonder whether their security forces are up to the task of protecting the country and whether their political institutions will survive intact.

“Such horrible blasts have occurred just one week after the American withdrawal, and then imagine what would happen after one month or one year after the Americans leaving,” said Abdul Rahman Qassim, a 46-year-old lawyer in the northern city of Mosul.